Data and Coding In todays lesson we will

Data and Coding In today’s lesson we will look at: • The difference between data and information • How we can code data to make it easier to process • The advantages and disadvantages of coding data

What are Data? Data is a collection of raw facts representing things or events that have happened. In ICT, we usually say that data is made up from four basic types: • Numbers • Text • Images • Sound

What is Information? • Information is data that have been processed to make them meaningful and useful • Data + Meaning = Information • Another way to add meaning is to process the data. • For example, individual exam marks are raw data, but if you were to process those to say that the average mark for the class was 53%, or that boys did better than girls, or that 76% of the students in your school got a grade A or B, then that is information!

Coding Data • Processing turns data into information • Sometimes you might want to take details that you have gathered and store them as data on a computer – this is called coding • How do you code the data to make them easy to process, without losing their meaning?

Example • Imagine you ask 30 people in a class the following question: What colour is your hair? ____ • How many different answer would you get? • Would the answers be easy for a computer to process? • What would be the difference if you asked: Please select your hair colour: • Brown • Blonde • Red

Coding Data • Data stored in a computer is often coded • Coding categorises data and can replace long, description strings with a few letters or numbers (or both!) • You are probably familiar with examples such as F for female and M for male • Some things are easier to code than others – e. g. opinions

Coding Example • Often surveys have questions like this: • Computing lessons are brilliant! • Disagree strongly • Disagree • Neither agree nor disagree • Agree strongly • How would you store the responses on a computer? • What would the user interface look like?

Coding - Advantages Data are often coded because: • It is quicker to enter into the computer • It require less disc space to store, and less memory to process • It can make processing easier – or possible – as there will be fewer responses • It improves the consistency of the data as spelling mistakes are less likely • Validation is easier to apply

Coding - Disadvantages Coding also has some negative effects : • The data stored on the computer might be more difficult for a human to interpret and process • Data are coarsened by forcing it all into categories – there might not be a category that matches what you want to record – e. g. hair colour • The same can be true of rounding numbers – the intervals or numbers of categories is called the granularity – this needs to be chosen carefully to maintain the quality of the information